To arrive at their new estimate, the University of Lorraine researchers analyzed xenon gas found in quartz from South Africa and Australia -- samples the scientists likened to "time capsules" since they provide a glimpse of the Earth's distant past.

How confident are the researchers of their finding? Not super-confident. They acknowledged that the 60 million year figure may be off by as much as 20 million years.

"It is not possible to give an exact date for the formation of the Earth," study co-author Dr. Guillaume Avice said in a written statement. "What this work does is to show that the Earth is older than we thought, by around 60 [million years]. The composition of the gases we are looking at changes according the conditions they are found in, which of course depend on the major events in Earth's history."

CORRECTION: An earlier version of this post incorrectly stated that previous estimates said the earth and moon had formed 100 years -- instead of 100 million years -- after the formation of the solar system.